Optical networking systems that communicate information over fiber optic links are common place. Examples of optical networking systems include passive optical networks (PONs) and Active Ethernet (AE) networks. Each type of optical networking system communicates information in accordance with an optical layer physical transport standard, sometimes referred to as an optical physical layer access standard. Various examples of PON physical layer transport standards include baseband PON (BPON) and gigabit PON (GPON). The PON standards may operate at different transfer rates. For example, the BPON standard specifies a transfer rate of 622 mega-bits per second (Mbps) and the GPON standard specifies transfer rates of 1.2 giga-bits per second (Gbps) or 2.4 Gbps. The AE standard specifies a transfer rate of 1.2 Gbps. In addition to transfer rates, the various standards also define maximum and minimum transmit and receive optical power levels, i.e., physical layer requirements. The various standards also define the manner in which the information is packaged for transmission and reception, i.e., data link layer requirements.
An optical networking system ordinarily includes either an optical line terminal (OLT), or an optical Ethernet switch (OES) with bi-directional optical interface located at or near a central office (CO) that transmits downstream voice, video, and/or data information to an optical network terminal (ONT) located at a subscriber premises such as a house or business. The ONT transmits upstream voice and/or data information from the subscriber premises to the OLT or OES. Generally, one OLT or OES transmits downstream information to multiple ONTs and receives upstream information from the multiple ONTs. In a PON, optical splitters and combiners are used to communicate optical signals among several ONTs and an OLT via the same optical fiber link. In an AE network, one or more optical Ethernet switches permit optical signals to be directed to individual ONTs via optical fiber links dedicated to the ONTs. In each case, the PON or AE ONT is configured to support the pertinent optical physical layer transport standard.